CONVOLUTIONAL AND EPHEMERAL DATACHAINS
1. A system, comprising:
- a computing node configured todetermine a data point trigger has occurred at a particular block cycle of a blockchain;
initiate a sidechain to store subsequent entries based on the data point trigger, wherein a genesis block of the sidechain comprises one or more relevant data fields from the blockchain;
initiate a sidechain smart contract to manage data entries submitted to the sidechain;
store the data entries in the sidechain for a conditional period; and
when the conditional period has matured, convolute the sidechain into the blockchain.
An example operation may include one or more of determining a data point trigger has occurred at a particular block cycle of a blockchain, initiating a sidechain to store subsequent entries based on the data point trigger, and a genesis block of the sidechain includes one or more relevant data fields from the blockchain, initiating a sidechain smart contract to manage data entries submitted to the sidechain, storing the data entries in the sidechain for a conditional period, and when the conditional period has matured, convoluting the sidechain into the blockchain.
- 1. A system, comprising:
a computing node configured to determine a data point trigger has occurred at a particular block cycle of a blockchain; initiate a sidechain to store subsequent entries based on the data point trigger, wherein a genesis block of the sidechain comprises one or more relevant data fields from the blockchain; initiate a sidechain smart contract to manage data entries submitted to the sidechain; store the data entries in the sidechain for a conditional period; and when the conditional period has matured, convolute the sidechain into the blockchain.
- View Dependent Claims (2, 3, 4, 5, 6, 7)
- 8. A method, comprising:
determining a data point trigger has occurred at a particular block cycle of a blockchain; initiating a sidechain to store subsequent entries based on the data point trigger, wherein a genesis block of the sidechain comprises one or more relevant data fields from the blockchain; initiating a sidechain smart contract to manage data entries submitted to the sidechain; storing the data entries in the sidechain for a conditional period; and when the conditional period has matured, convoluting the sidechain into the blockchain.
- View Dependent Claims (9, 10, 11, 12, 13, 14)
- 15. A non-transitory computer readable storage medium configured to store instructions that when executed cause a processor to perform:
determining a data point trigger has occurred at a particular block cycle of a blockchain; initiating a sidechain smart contract to manage data entries submitted to the sidechain; storing the data entries in the sidechain for a conditional period; and when the conditional period has matured, convoluting the sidechain into the blockchain.
- View Dependent Claims (16, 17, 18, 19, 20)
This application generally relates to ephemeral datachains, and more particularly, convolutional and ephemeral datachains.
A centralized database stores and maintains data in one single database (e.g., database server) at one location. This location is often a central computer, for example, a desktop central processing unit (CPU), a server CPU, or a mainframe computer. Information stored on a centralized database is typically accessible from multiple different points. Multiple users or client workstations can work simultaneously on the centralized database, for example, based on a client/server configuration. A centralized database is easy to manage, maintain, and control, especially for purposes of security because of its single location. Within a centralized database, data redundancy is minimized as a single storing place of all data also implies that a given set of data only has one primary record.
However, a centralized database suffers from significant drawbacks. For example, a centralized database has a single point of failure. In particular, if there are no fault-tolerance considerations and a hardware failure occurs (for example a hardware, firmware, and/or a software failure), all data within the database is lost and work of all users is interrupted. In addition, centralized databases are highly dependent on network connectivity. As a result, the slower the connection, the amount of time needed for each database access is increased. Another drawback is the occurrence of bottlenecks when a centralized database experiences high traffic due to a single location. Furthermore, a centralized database provides limited access to data because only one copy of the data is maintained by the database. As a result, multiple devices cannot access the same piece of data at the same time without creating significant problems or risk overwriting stored data. Furthermore, because a database storage system has minimal to no data redundancy, data that is unexpectedly lost is very difficult to retrieve other than through manual operation from back-up storage.
Conventionally, a centralized database is limited by its ability to manage dynamic changes, such as sub-chains of data which may be needed on a temporary basis to manage dynamic data management requirements. As such, what is needed is a solution to overcome these significant drawbacks.
One example embodiment provides a system including a computing node configured to determine a data point trigger has occurred at a particular block cycle of a blockchain, initiate a sidechain to store subsequent entries based on the data point trigger, and a genesis block of the sidechain comprises one or more relevant data fields from the blockchain, initiate a sidechain smart contract to manage data entries submitted to the sidechain, store the data entries in the sidechain for a conditional period, and when the conditional period has matured, convolute the sidechain into the blockchain.
Another example embodiment provides a method that includes determining a data point trigger has occurred at a particular block cycle of a blockchain, initiating a sidechain to store subsequent entries based on the data point trigger, and a genesis block of the sidechain comprises one or more relevant data fields from the blockchain, initiating a sidechain smart contract to manage data entries submitted to the sidechain, storing the data entries in the sidechain for a conditional period, and when the conditional period has matured, convoluting the sidechain into the blockchain.
Yet another example embodiment includes a non-transitory computer readable storage medium configured to store instructions that when executed cause a processor to perform determining a data point trigger has occurred at a particular block cycle of a blockchain, initiating a sidechain to store subsequent entries based on the data point trigger, and a genesis block of the sidechain comprises one or more relevant data fields from the blockchain, initiating a sidechain smart contract to manage data entries submitted to the sidechain, storing the data entries in the sidechain for a conditional period, and when the conditional period has matured, convoluting the sidechain into the blockchain.
It will be readily understood that the instant components, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of at least one of a method, apparatus, non-transitory computer readable medium and system, as represented in the attached figures, is not intended to limit the scope of the application as claimed but is merely representative of selected embodiments.
The instant features, structures, or characteristics as described throughout this specification may be combined in any suitable manner in one or more embodiments. For example, the usage of the phrases “example embodiments”, “some embodiments”, or other similar language, throughout this specification refers to the fact that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment. Thus, appearances of the phrases “example embodiments”, “in some embodiments”, “in other embodiments”, or other similar language, throughout this specification do not necessarily all refer to the same group of embodiments, and the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
In addition, while the term “message” may have been used in the description of embodiments, the application may be applied to many types of network data, such as, packet, frame, datagram, etc. The term “message” also includes packet, frame, datagram, and any equivalents thereof. Furthermore, while certain types of messages and signaling may be depicted in exemplary embodiments they are not limited to a certain type of message, and the application is not limited to a certain type of signaling.
Example embodiments provide methods, systems, components, non-transitory computer readable media, devices, and/or networks, which provide, for permissioned blockchain implementations, a mechanism to manage a main distributed ledger (i.e., blockchain) by spawning new ephemeral blockchains (sidechains) with a custom execution code (i.e., smart contracts) on an as-needed basis. As a result, select portions of the main/root blockchain can be deposited into the sidechains. The sidechains may operate in parallel to the existing and concurrent operation of the main ‘blockchain’. When a sidechain finalizes its intended purpose (i.e., store membership information for a new set of members, export private information away from the blockchain as it is received, export large files which are not practical to store in the blockchain, etc.), the sidechain may convolute/retract into a compact form by retracting its contents into the root blockchain thus preserving consistency of assets across an entire blockchain graph. The examples provide a computer-implemented method for accessing, developing and maintaining a decentralized database through a peer-to-peer network, to preserve the original state of data inputs while providing flexibility with creating releasable sidechains and thus permitting a blockchain to scale accordingly.
A decentralized database is a distributed storage system which includes multiple nodes that communicate with each other. A blockchain is an example of a decentralized database which includes an append-only immutable data structure resembling a distributed ledger capable of maintaining records between mutually untrusted parties. The untrusted parties are referred to herein as peers or peer nodes. Each peer maintains a copy of the database records and no single peer can modify the database records without a consensus being reached among the distributed peers. For example, the peers may execute a consensus protocol to validate blockchain storage entries, group the storage entries into blocks, and build a hash chain over the blocks. This process forms the ledger by ordering the storage entries, as is necessary, for consistency. In a public or permission-less blockchain, anyone can participate without a specific identity. Public blockchains often involve native cryptocurrency and use consensus based on various protocols such as Proof of Work (PoW). On the other hand, a permissioned blockchain database provides a system which can secure inter-actions among a group of entities which share a common goal but which do not fully trust one another, such as businesses that exchange funds, goods, information, and the like.
A blockchain operates arbitrary, programmable logic, tailored to a decentralized storage scheme and referred to as “smart contracts” or “chaincodes.” In some cases, specialized chaincodes may exist for management functions and parameters which are referred to as system chaincode. Smart contracts are trusted distributed applications which leverage tamper-proof properties of the blockchain database and an underlying agreement between nodes which is referred to as an endorsement or endorsement policy. In general, blockchain entries typically must be “endorsed” before being committed to the blockchain while entries which are not endorsed are disregarded. A typical endorsement policy allows chaincode to specify endorsers for an entry in the form of a set of peer nodes that are necessary for endorsement. When a client sends the entry to the peers specified in the endorsement policy, the entry is executed to validate the entry. After validation, the entries enter an ordering phase in which a consensus protocol is used to produce an ordered sequence of endorsed entries grouped into blocks.
Nodes are the communication entities of the blockchain system. A “node” may perform a logical function in the sense that multiple nodes of different types can run on the same physical server. Nodes are grouped in trust domains and are associated with logical entities that control them in various ways. Nodes may include different types, such as a client or submitting-client node which submits an entry-invocation to an endorser (e.g., peer), and broadcasts entry-proposals to an ordering service (e.g., ordering node). Another type of node is a peer node which can receive client submitted entries, commit the entries and maintain a state and a copy of the ledger of blockchain entries. Peers can also have the role of an endorser, although it is not a requirement. An ordering-service-node or orderer is a node running the communication service for all nodes, and which implements a delivery guarantee, such as a broadcast to each of the peer nodes in the system when committing entries and modifying a world state of the blockchain, which is another name for the initial blockchain entry which normally includes control and setup information.
A ledger is a sequenced, tamper-resistant record of all state transitions of a blockchain. State transitions may result from chaincode invocations (i.e., entries) submitted by participating parties (e.g., client nodes, ordering nodes, endorser nodes, peer nodes, etc.). An entry may result in a set of asset key-value pairs being committed to the ledger as one or more operands, such as creates, updates, deletes, and the like. The ledger includes a blockchain (also referred to as a chain) which is used to store an immutable, sequenced record in blocks. The ledger also includes a state database which maintains a current state of the blockchain. There is typically one ledger per channel. Each peer node maintains a copy of the ledger for each channel of which they are a member.
A chain is an entry log which is structured as hash-linked blocks, and each block contains a sequence of N entries where N is equal to or greater than one. The block header includes a hash of the block'"'"'s entries, as well as a hash of the prior block'"'"'s header. In this way, all entries on the ledger may be sequenced and cryptographically linked together. Accordingly, it is not possible to tamper with the ledger data without breaking the hash links. A hash of a most recently added blockchain block represents every entry on the chain that has come before it, making it possible to ensure that all peer nodes are in a consistent and trusted state. The chain may be stored on a peer node file system (i.e., local, attached storage, cloud, etc.), efficiently supporting the append-only nature of the blockchain workload.
The current state of the immutable ledger represents the latest values for all keys that are included in the chain entry log. Because the current state represents the latest key values known to a channel, it is sometimes referred to as a world state. Chaincode invocations execute entries against the current state data of the ledger. To make these chaincode interactions efficient, the latest values of the keys may be stored in a state database. The state database may be simply an indexed view into the chain'"'"'s entry log, it can therefore be regenerated from the chain at any time. The state database may automatically be recovered (or generated if needed) upon peer node startup, and before entries are accepted.
Blockchain is different from a traditional database in that the blockchain is not a central storage but rather a decentralized, immutable, and secure storage, where nodes must share in changes to records in the storage. Some properties that are inherent in blockchain and which help implement the blockchain include, but are not limited to, an immutable ledger, smart contracts, security, privacy, decentralization, consensus, endorsement, accessibility, and the like, which are further described herein.
The example embodiments provide a new solution to scale-up a blockchain infrastructure and introduce a releasable sidechain transaction log to cover a variety of use cases for optimal blockchain performance. The embodiments include a modification to a blockchain core structure. One example approach may include a blockchain that is decentralized/distributed and where this blockchain is highly available by multiple parties, as well as a root blockchain that relies on transaction log immutability sidechains. The consensus approach for approval is used for the main blockchain and the sidechains as well.
Optimization may include minimizing a size of a transaction log data by using sidechains. Regular nodes of the blockchain network (i.e., light nodes) are not required to download sidechains or compute data on them whenever a new transaction is identified. Light nodes still perform verification/validity but convoluted sidechains are disposable by nature, so the amount of data required to be maintained locally is significantly less by comparison with traditional blockchains. This approach provides optimal computing speeds, communications and processing requirements. An original root chain genesis includes settings for sidechains, such as limits to a maximum number of sidechains permitted, if open/closed sidechains are supported, smart contracts supported in the sidechains, maximum owners/participants per private sidechain etc.
A sidechain genesis block may include standard fields, a type of sidechain (i.e., visibility: open, closed), an owners'"'"' list, if applicable, private chain designation, participant list, if applicable, a difficulty field, which is inherited from the main chain, a hash from the main root chain, and an owner signature. A sidechain transaction/entry may include a sidechain ID from the genesis block, a type (i.e., regular, convoluted), a script part, which is is updated to support sidechain validation (i.e., owner'"'"'s signature, list of participants, visibility constraints etc.), a sidechain tail transaction ID, if applicable. The transaction block header may include a number of convoluted transactions, a list of convoluted transactions, a range along with a sidechain ID, a sidechain ID for a block, and a difficulty (if applicable) can be adjusted on a per sidechain basis.
Example triggers, as conditions precedent to initiating a sidechain, may include, for instance, two or more parties seeking to have quick access to asset transfers, and thus when the asset is identified in the blockchain transaction, it may be moved to a sidechain once it is identified as having a time sensitive asset flag or a pre-stored party'"'"'s preference parameter set by one or more of the parties. Once the flag is identified, the asset and the corresponding transaction may be moved to a sidechain, so the asset transfer can occur at a higher speed so a transaction log, separate from the root (main) chain, can be updated accordingly to provide the parties with a finalized blockchain entry. Parties can continue to move and transfer assets via sidechain transactions as long as desired or until the sidechain owner decides to convolute the data into the blockchain and collapse the sidechain. In one example, the initial sidechain transaction which spawned the sidechain should contain a signature for the sidechain owner (i.e., initiator). Optionally, there may be other co-owners/actors being added to the sidechain membership group to signify trust between sidechain parties. An open sidechain indicates that anyone can transfer assets to the sidechain while closed sidechains permit only owners/co-owners/members specifically identified in a list of the blockchain to participate.
Blockchain miners can also be initiators of a sidechain and there could be automatic triggers in case of an open non-enhanced private blockchain structure configured through a genesis block of the sidechain. Therefore, a blockchain can have pre-configured triggers for sidechains, such as, for example, when a number of transactions between two or more parties is greater than a particular threshold then their assets are moved to a sidechain to provide a more optimal processing structure. Another example may include natural root chain ‘sharding’, which may be described as the off-loading of blockchain data and spawning of sidechains and distributing members among those sidechains created. Triggers for sidechain access can also be performed by miners either through smart contract execution or by the member actions. Those sidechains would remain open as there is a capability for asset owners to access the blockchain and various sidechains.
The first sidechain 130 is illustrated as having been created during the existence of block 2 (106) on the main blockchain 120. The data point trigger was identified from a context of a smart contract used to manage the blockchain 120. The identification of the data point trigger caused the sidechain to be launched. The lifecycle of the sidechain may be based on a particular threshold such as a time threshold (e.g., 30 minutes, etc.), a number of blocks threshold (e.g., 5 blocks, etc.), a frequency of data occurrences threshold (e.g., organization A identified from majority of last 100 transactions, etc.). Once the sidechain 130 (blocks 122-126) has run its course and is no longer needed per the instructions of the sidechain smart contract, the decision may be made to convolute the sidechain into the blockchain 120. This process of convolution 132 may include taking portions of the sidechain data and incorporating it into the blockchain 120 (blocks 102-116), such as metadata portions of the various entries (e.g., parties, asset data, dates, values, etc.) submitted to the sidechain 130 so that those entries can be identified for audit purposes and recalled in their entirety if necessary. The entire sidechain data may be brought into the main blockchain during an off-cycle time (e.g., midnight to 8 am). In this example, the sidechain is created to offload the peak use periods of the blockchain 120 and then the data is eventually brought back to the blockchain in off-peak periods of time. Another sidechain 150 is created during the cycle of block B4 110. This second sidechain 150 is active for five blocks (142-150) and for a period of three blocks (110-114) of the main blockchain 120 before being convoluted 152 into the root chain at block 114. Each blockchain and sidechain has its own smart contract used to define its own entries/transactions. For example, in order to be effective and optimal, the smart contract for the first sidechain may identify the specific data points which would trigger transactions to be entered into the sidechain 130, all other transaction data may be suitable for the blockchain transactions of the main blockchain 120.
In one example embodiment, the main/root blockchain 120 permits any system participant to initiate a process of spawning new sidechains with custom execution logic. The conditions for when to create a sidechain may be part of the main blockchain smart contract. However, once created, the sidechain may have its own smart contract created to define the purpose and actions of the sidechain data and entries, and when to stop and close the sidechain from subsequent entries. The sidechain can be created by a blockchain participant depositing assets into the sidechain from the root chain (e.g., “sharding”), which cross-references transactions in the sidechain and the main chain by references to the main chain data placed into the sidechain data. Sidechains can share a common miner pool for finalization management purposes. Once created, the sidechain can run in parallel to the main blockchain so that both chains are being allocated with new entries at the same time. At the time of the sidechain finalization, which can be determined by execution code (e.g., expiration date/time, or other data point trigger, etc.) the sidechain data is then convoluted into the root blockchain so the sidechain is actually retracted into the root chain for long term data preservation.
Data convolution may provide partial data, complete data, and/or metadata specific parameters only (e.g., pointers), when collapsing a sidechain into the root blockchain. One example may include, a sidechain ‘S1’ with assets which transfer between parties A (sidechain value 10), and B (sidechain value 10) in a scenario: S1: A→B, 2 (A=8, B=12), S1: A→B, 1 (A=7, B=13), S1: B→A, 8 (A=15, B=7), and S1: A→B, 1 (A=14, B=8), with four transactions in total, and the result values are the only values that matter, so four transaction can be convoluted into either 1 or 2 depending on a blockchain transaction structure. If the transfers support batches, then one single transaction can have multiple transfers confirmed based on a final result, for example, there will be two convoluted transactions in the root chain as follows: A->B, 2, S1 and B->A, 4, S1, which leads to the same identical value at the end of the transaction record (A=14, B=8) and both transactions are part of the same mining block. Less data from multiple transactions leads to increased efficiency when post-processing sidechain data convolution occurs.
The blockchain base or platform 212 may include various layers of blockchain data, services (e.g., cryptographic trust services, virtual execution environment, etc.), and underpinning physical computer infrastructure that may be used to receive and store new entries and provide access to auditors which are seeking to access data entries. The blockchain layer 216 may expose an interface that provides access to the virtual execution environment necessary to process the program code and engage the physical infrastructure 214. Cryptographic trust services 218 may be used to verify entries such as asset exchange entries and keep information private.
The blockchain architecture configuration of
Within chaincode, a smart contract may be created via a high-level application and programming language, and then written to a block in the blockchain. The smart contract may include executable code which is registered, stored, and/or replicated with a blockchain (e.g., distributed network of blockchain peers). An entry is an execution of the smart contract code which can be performed in response to conditions associated with the smart contract being satisfied. The executing of the smart contract may trigger a trusted modification(s) to a state of a digital blockchain ledger. The modification(s) to the blockchain ledger caused by the smart contract execution may be automatically replicated throughout the distributed network of blockchain peers through one or more consensus protocols.
The smart contract may write data to the blockchain in the format of key-value pairs. Furthermore, the smart contract code can read the values stored in a blockchain and use them in application operations. The smart contract code can write the output of various logic operations into the blockchain. The code may be used to create a temporary data structure in a virtual machine or other computing platform. Data written to the blockchain can be public and/or can be encrypted and maintained as private. The temporary data that is used/generated by the smart contract is held in memory by the supplied execution environment, then deleted once the data needed for the blockchain is identified.
A chaincode may include the code interpretation of a smart contract, with additional features. As described herein, the chaincode may be program code deployed on a computing network, where it is executed and validated by chain validators together during a consensus process. The chaincode receives a hash and retrieves from the blockchain a hash associated with the data template created by use of a previously stored feature extractor. If the hashes of the hash identifier and the hash created from the stored identifier template data match, then the chaincode sends an authorization key to the requested service. The chaincode may write to the blockchain data associated with the cryptographic details.
Referring again to
In response, the endorsing peer node 281 may verify (a) that the entry proposal is well formed, (b) the entry has not been submitted already in the past (replay-attack protection), (c) the signature is valid, and (d) that the submitter (client 260, in the example) is properly authorized to perform the proposed operation on that channel. The endorsing peer node 281 may take the entry proposal inputs as arguments to the invoked chaincode function. The chaincode is then executed against a current state database to produce entry results including a response value, read set, and write set. However, no updates are made to the ledger at this point. In 292, the set of values, along with the endorsing peer node'"'"'s 281 signature is passed back as a proposal response 292 to the SDK of the client 260 which parses the payload for the application to consume.
In response, the application of the client 260 inspects/verifies the endorsing peers signatures and compares the proposal responses to determine if the proposal response is the same. If the chaincode only queried the ledger, the application would inspect the query response and would typically not submit the entry to the ordering node service 284. If the client application intends to submit the entry to the ordering node service 284 to update the ledger, the application determines if the specified endorsement policy has been fulfilled before submitting (i.e., did all peer nodes necessary for the entry endorse the entry). Here, the client may include only one of multiple parties to the entry. In this case, each client may have their own endorsing node, and each endorsing node will need to endorse the entry. The architecture is such that even if an application selects not to inspect responses or otherwise forwards an unendorsed entry, the endorsement policy will still be enforced by peers and upheld at the commit validation phase.
After successful inspection, in step 293 the client 260 assembles endorsements into an entry and broadcasts the entry proposal and response within an entry message to the ordering node 284. The entry may contain the read/write sets, the endorsing peers signatures and a channel ID. The ordering node 284 does not need to inspect the entire content of an entry in order to perform its operation, instead the ordering node 284 may simply receive entries from all channels in the network, order them chronologically by channel, and create blocks of entries per channel.
The blocks of the entry are delivered from the ordering node 284 to all peer nodes 281-283 on the channel. The entries 294 within the block are validated to ensure any endorsement policy is fulfilled and to ensure that there have been no changes to ledger state for read set variables since the read set was generated by the entry execution. Entries in the block are tagged as being valid or invalid. Furthermore, in step 295 each peer node 281-283 appends the block to the channel'"'"'s chain, and for each valid entry the write sets are committed to current state database. An event is emitted, to notify the client application that the entry (invocation) has been immutably appended to the chain, as well as to notify whether the entry was validated or invalidated.
A blockchain developer system 316 writes chaincode and client-side applications. The blockchain developer system 316 can deploy chaincode directly to the network through a REST interface. To include credentials from a traditional data source 330 in chaincode, the developer system 316 could use an out-of-band connection to access the data. In this example, the blockchain user 302 connects to the network through a peer node 312. Before proceeding with any entries, the peer node 312 retrieves the user'"'"'s enrollment and entry certificates from the certificate authority 318. In some cases, blockchain users must possess these digital certificates in order to transact on the permissioned blockchain network 310. Meanwhile, a user attempting to drive chaincode may be required to verify their credentials on the traditional data source 330. To confirm the user'"'"'s authorization, chaincode can use an out-of-band connection to this data through a traditional processing platform 320.
In addition to just convoluting the content of the sidechain into the blockchain at the sidechain'"'"'s maturity point, the assets stored in the sidechain may require a threshold level of proof prior to being accepted into the blockchain. The proofs may be associated with a certain type of encryption, a certain amount of endorsements from blockchain peers, a particular asset type and/or a current asset status, such as approved, completed, transferred, etc.
The above embodiments may be implemented in hardware, in a computer program executed by a processor, in firmware, or in a combination of the above. A computer program may be embodied on a computer readable medium, such as a storage medium. For example, a computer program may reside in random access memory (“RAM”), flash memory, read-only memory (“ROM”), erasable programmable read-only memory (“EPROM”), electrically erasable programmable read-only memory (“EEPROM”), registers, hard disk, a removable disk, a compact disk read-only memory (“CD-ROM”), or any other form of storage medium known in the art.
An exemplary storage medium may be coupled to the processor such that the processor may read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an application specific integrated circuit (“ASIC”). In the alternative, the processor and the storage medium may reside as discrete components. For example,
The distributed ledger 730 includes a blockchain 732 which stores immutable, sequenced records in blocks, and a state database 734 (current world state) maintaining a current state of the blockchain 732. One distributed ledger 730 may exist per channel and each peer maintains its own copy of the distributed ledger 730 for each channel of which they are a member. The blockchain 732 is an entry log, structured as hash-linked blocks where each block contains a sequence of N entries. Blocks may include various components such as shown in
The current state of the blockchain 732 and the distributed ledger 732 may be stored in the state database 734. Here, the current state data represents the latest values for all keys ever included in the chain entry log of the blockchain 732. Chaincode invocations execute entries against the current state in the state database 734. To make these chaincode interactions extremely efficient, the latest values of all keys are stored in the state database 734. The state database 734 may include an indexed view into the entry log of the blockchain 732, it can therefore be regenerated from the chain at any time. The state database 734 may automatically get recovered (or generated if needed) upon peer startup, before entries are accepted.
Endorsing nodes receive entries from clients and endorse the entry based on simulated results. Endorsing nodes hold smart contracts which simulate the entry proposals. When an endorsing node endorses an entry, the endorsing nodes creates an entry endorsement which is a signed response from the endorsing node to the client application indicating the endorsement of the simulated entry. The method of endorsing an entry depends on an endorsement policy which may be specified within chaincode. An example of an endorsement policy is “the majority of endorsing peers must endorse the entry.” Different channels may have different endorsement policies. Endorsed entries are forward by the client application to ordering service 710.
The ordering service 710 accepts endorsed entries, orders them into a block, and delivers the blocks to the committing peers. For example, the ordering service 710 may initiate a new block when a threshold of entries has been reached, a timer times out, or another condition. In the example of
The ordering service 710 may be made up of a cluster of orderers. The ordering service 710 does not process entries, smart contracts, or maintain the shared ledger. Rather, the ordering service 710 may accept the endorsed entries and specifies the order in which those entries are committed to the distributed ledger 730. The architecture of the blockchain network may be designed such that the specific implementation of ‘ordering’ (e.g., Solo, Kafka, BFT, etc.) becomes a pluggable component.
Entries are written to the distributed ledger 730 in a consistent order. The order of entries is established to ensure that the updates to the state database 734 are valid when they are committed to the network. Unlike a cryptocurrency blockchain system (e.g., Bitcoin, etc.) where ordering occurs through the solving of a cryptographic puzzle, or mining, in this example the parties of the distributed ledger 730 may choose the ordering mechanism that best suits that network.
When the ordering service 710 initializes a new block 750, the new block 750 may be broadcast to committing peers (e.g., blockchain nodes 721, 722, and 723). In response, each committing peer validates the entry within the new block 750 by checking to make sure that the read set and the write set still match the current world state in the state database 734. Specifically, the committing peer can determine whether the read data that existed when the endorsers simulated the entry is identical to the current world state in the state database 734. When the committing peer validates the entry, the entry is written to the blockchain 732 on the distributed ledger 730, and the state database 734 is updated with the write data from the read-write set. If an entry fails, that is, if the committing peer finds that the read-write set does not match the current world state in the state database 734, the entry ordered into a block will still be included in that block, but it will be marked as invalid, and the state database 734 will not be updated.
The block data 770 may store entry information of each entry that is recorded within the block 750. For example, the entry data may include one or more of a type of the entry, a version, a timestamp, a channel ID of the distributed ledger 730, an entry ID, an epoch, a payload visibility, a chaincode path (deploy tx), a chaincode name, a chaincode version, input (chaincode and functions), a client (creator) identify such as a public key and certificate, a signature of the client, identities of endorsers, endorser signatures, a proposal hash, chaincode events, response status, namespace, a read set (list of key and version read by the entry, etc.), a write set (list of key and value, etc.), a start key, an end key, a list of keys, a Merkel tree query summary, and the like. The entry data may be stored for each of the N entries.
In some embodiments, the block data 770 may also store data 772 which adds additional information to the hash-linked chain of blocks in the blockchain 732. Accordingly, the data 772 can be stored in an immutable log of blocks on the distributed ledger 730. Some of the benefits of storing such data 772 are reflected in the various embodiments disclosed and depicted herein.
The block metadata 780 may store multiple fields of metadata (e.g., as a byte array, etc.). Metadata fields may include signature on block creation, a reference to a last configuration block, an entry filter identifying valid and invalid entries within the block, last offset persisted of an ordering service that ordered the block, and the like. The signature, the last configuration block, and the orderer metadata may be added by the ordering service 710. Meanwhile, a committer of the block (such as blockchain node 722) may add validity/invalidity information based on an endorsement policy, verification of read/write sets, and the like. The entry filter may include a byte array of a size equal to the number of entries in the block data 770 and a validation code identifying whether an entry was valid/invalid.
In computing node 800 there is a computer system/server 802, which is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well-known computing systems, environments, and/or configurations that may be suitable for use with computer system/server 802 include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, set top boxes, programmable consumer electronics, network PCs, minicomputer systems, mainframe computer systems, and distributed cloud computing environments that include any of the above systems or devices, and the like.
Computer system/server 802 may be described in the general context of computer system-executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system/server 802 may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices.
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The bus represents one or more of any of several types of bus structures, including a memory bus or memory controller, a peripheral bus, an accelerated graphics port, and a processor or local bus using any of a variety of bus architectures. By way of example, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Association (VESA) local bus, and Peripheral Component Interconnects (PCI) bus.
Computer system/server 802 typically includes a variety of computer system readable media. Such media may be any available media that is accessible by computer system/server 802, and it includes both volatile and non-volatile media, removable and non-removable media. System memory 806, in one embodiment, implements the flow diagrams of the other figures. The system memory 806 can include computer system readable media in the form of volatile memory, such as random-access memory (RAM) 810 and/or cache memory 812. Computer system/server 802 may further include other removable/non-removable, volatile/non-volatile computer system storage media. By way of example only, storage system 814 can be provided for reading from and writing to a non-removable, non-volatile magnetic media (not shown and typically called a “hard drive”). Although not shown, a magnetic disk drive for reading from and writing to a removable, non-volatile magnetic disk (e.g., a “floppy disk”), and an optical disk drive for reading from or writing to a removable, non-volatile optical disk such as a CD-ROM, DVD-ROM or other optical media can be provided. In such instances, each can be connected to the bus by one or more data media interfaces. As will be further depicted and described below, memory 806 may include at least one program product having a set (e.g., at least one) of program modules that are configured to carry out the functions of various embodiments of the application.
Program/utility 816, having a set (at least one) of program modules 818, may be stored in memory 806 by way of example, and not limitation, as well as an operating system, one or more application programs, other program modules, and program data. Each of the operating system, one or more application programs, other program modules, and program data or some combination thereof, may include an implementation of a networking environment. Program modules 818 generally carry out the functions and/or methodologies of various embodiments of the application as described herein.
As will be appreciated by one skilled in the art, aspects of the present application may be embodied as a system, method, or computer program product. Accordingly, aspects of the present application may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, aspects of the present application may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Computer system/server 802 may also communicate with one or more external devices 820 such as a keyboard, a pointing device, a display 822, etc.; one or more devices that enable a user to interact with computer system/server 802; and/or any devices (e.g., network card, modem, etc.) that enable computer system/server 802 to communicate with one or more other computing devices. Such communication can occur via I/O interfaces 824. Still yet, computer system/server 802 can communicate with one or more networks such as a local area network (LAN), a general wide area network (WAN), and/or a public network (e.g., the Internet) via network adapter 826. As depicted, network adapter 826 communicates with the other components of computer system/server 802 via a bus. It should be understood that although not shown, other hardware and/or software components could be used in conjunction with computer system/server 802. Examples, include, but are not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data archival storage systems, etc.
Although an exemplary embodiment of at least one of a system, method, and non-transitory computer readable medium has been illustrated in the accompanied drawings and described in the foregoing detailed description, it will be understood that the application is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions as set forth and defined by the following claims. For example, the capabilities of the system of the various figures can be performed by one or more of the modules or components described herein or in a distributed architecture and may include a transmitter, receiver or pair of both. For example, all or part of the functionality performed by the individual modules, may be performed by one or more of these modules. Further, the functionality described herein may be performed at various times and in relation to various events, internal or external to the modules or components. Also, the information sent between various modules can be sent between the modules via at least one of: a data network, the Internet, a voice network, an Internet Protocol network, a wireless device, a wired device and/or via plurality of protocols. Also, the messages sent or received by any of the modules may be sent or received directly and/or via one or more of the other modules.
One skilled in the art will appreciate that a “system” could be embodied as a personal computer, a server, a console, a personal digital assistant (PDA), a cell phone, a tablet computing device, a smartphone or any other suitable computing device, or combination of devices. Presenting the above-described functions as being performed by a “system” is not intended to limit the scope of the present application in any way but is intended to provide one example of many embodiments. Indeed, methods, systems and apparatuses disclosed herein may be implemented in localized and distributed forms consistent with computing technology.
It should be noted that some of the system features described in this specification have been presented as modules, in order to more particularly emphasize their implementation independence. For example, a module may be implemented as a hardware circuit comprising custom very large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A module may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, graphics processing units, or the like.
A module may also be at least partially implemented in software for execution by various types of processors. An identified unit of executable code may, for instance, comprise one or more physical or logical blocks of computer instructions that may, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified module need not be physically located together but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the module and achieve the stated purpose for the module. Further, modules may be stored on a computer-readable medium, which may be, for instance, a hard disk drive, flash device, random access memory (RAM), tape, or any other such medium used to store data.
Indeed, a module of executable code could be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within modules and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.
It will be readily understood that the components of the application, as generally described and illustrated in the figures herein, may be arranged and designed in a wide variety of different configurations. Thus, the detailed description of the embodiments is not intended to limit the scope of the application as claimed but is merely representative of selected embodiments of the application.
One having ordinary skill in the art will readily understand that the above may be practiced with steps in a different order, and/or with hardware elements in configurations that are different than those which are disclosed. Therefore, although the application has been described based upon these preferred embodiments, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions would be apparent.
While preferred embodiments of the present application have been described, it is to be understood that the embodiments described are illustrative only and the scope of the application is to be defined solely by the appended claims when considered with a full range of equivalents and modifications (e.g., protocols, hardware devices, software platforms etc.) thereto.